Hybrid vehicles that use a motor include a motor control unit for controlling the motor and a direct current (DC)-DC converter.
The DC-DC converter that is a device for converting power, can convert a DC into an alternating current (AC), can transform and then rectify the current, and can output a DC. In this procedure, a large amount of heat is generated in the DC-DC converter. Thus, a cooling system is provided to eliminate heat from the DC-DC converter. The cooling system can be disposed at a lower portion of a case and can absorb heat generated in components of the cooling system.
In this case, when a contact between electronic components and the case is non-uniform, cooling efficiency may be lowered. In particular, when areas in which a plurality of switches for switching voltages, for example, metal oxide semiconductor field effect transistors (MOSFETs) contact the case, are different from one another, cooling efficiency of each of the plurality of switches is changed so that performance of the DC-DC converter may be deteriorated.